1. Field of the Invention
The present invention relates to a wafer carrier including a lower unit on which a semiconductor wafer is placed and an upper unit forming a sealed chamber for housing the semiconductor wafer between the upper unit and the lower unit.
2. Description of Related Art
A manufacturing process of a SMIF (Standard Mechanical Interface) system in which air pollution control is not uniformly directed to the entire manufacturing process of a semiconductor device but is focused on only a space where a semiconductor wafer exists is proposed. In the manufacturing process of the SMIF system, a sealed chamber called a wafer carrier is used at the time of carrying the semiconductor wafer to each processing equipment or storing the semiconductor wafer.
For example, a wafer carrier including a lower unit on which a semiconductor wafer is placed and an upper unit detachably attached to the lower unit and forming a sealed chamber for housing the semiconductor wafer between the upper unit and the lower unit is known (refer to Japanese Unexamined Patent Application Publication No. 2011-108698). The lower unit is fixed to the upper unit by engaging a lock lever provided in the upper unit with a lower surface of the lower unit.
However, for example, in a process of carrying the wafer carrier to each processing equipment, the lower surface of the lower unit is exposed to the air. Accordingly, dust elements are liable to be adhered to the lock lever engaged with the lower surface of the lower unit. Furthermore, a clean chamber is formed on the lower surface side of the lower unit at the time of opening and closing the wafer carrier. Accordingly, dust elements adhered to the lock lever or dust elements generated by the lock lever may enter the clean chamber.